At first, this one looks like the same old "pick a card, any card" key card scam you've seen before on Scam School. Your mark picks a card, looks at it, and puts it back, and cuts the deck. Then you look at the whole deck, "memorizing" it in a mere 10 seconds. At this point, ask the mark to move his card somewhere else in the deck. Then you shuffle the deck, which means it couldn't possibly be a key card trick! Unless...

It's a TWO key card trick. You have to memorize the top and bottom cards for this one. Any cards between them could be the card your mark picked. keep those cards in your head while you shuffle, and when you look at the cards again, it will be easy to tell which one your dupe has moved.